Why is lambretta ignition so unreliable?

[coaster]

Just to add to this debate, I was considering winding my own LT coils several years ago so decided to unwind one to count the coils. What I found was that the coil windings only had intermittant aplication of lacquer meaning that most of the winding was unsuported and therefore would wear away with vibration. That lacquer needs to be applied automatically throughout the winding proces but I suspect that some Indian aftermarket suppliers lust dab with a brush just enough to hold the windings in place until the outer tape goes on.
Other failure points for ANY stator are the wire and earth connections. The little earth tabs ared only secured by a long rivet which passes right thhrough the laminated core and are sometimeds loose and benefit from peening with a small hammer. The LT coil wire to the green wire is VERY fragile and needs to be supported by a dollop of Araldite. I also Araldite all wires to the nearest solid support as vibration is the killer here. I have done this to BGM and Scootronics stators and both have been trouble free.
Re VAPE reliability, its true that relatively few are in use on Lambrettas but they are a motorcycle derived system and are fitted to thousounds of bkes including Vespas so maybe the claims a viable after all

[Adam_Winstone]

^... agreed.

The extremely thin gauge wire of the LT, on a bike that vibrates, is why this is typically the point of failure on the traditional 12V electronic systems. Yes, better winding / resin procedures can seriously improve reliability, which is why Ducati LT coils on genuine Vespa and AF 80s kits have been reliable for so long, however, the idea of moving from thin gauge LT windings to thicker lighting coil windings is a worthy one [Readspeed Lukas CDI].

[Micky67keane]

Aaah so it maybe just loose connections...
Something to investigate once swapped,maybe then keep as a spare.
Thank you

[Micky67keane]

Thanks Adam

[Adam_Winstone]

... if you do have a failed LT coil (all too common) and decide that you want to repair it by replacing the LT coil, I note that BuzzSolomoto is selling my favourite CEAB LT coils, which I have used for years and IMO are equal in quality to the genuine / factory fitted Ducati LTs.

If you did decide to go down that route, Buzz is right to have highlighted on his Ebay advert that they are straight swap for Vespa / 80s AF stators, however, for use on Indian Lambretta stators you will need to cut a couple of laminate plates off the laminate core so that the CEAB fits. This is easy to do with cutting discs in a Dremel (or other). You will still need to be able to use a soldering iron and as Coaster has said, you'll want to put a dab of epoxy on some points to avoid vibration fracture in the future.

Rebuilding stators is one of my personal Lambretta perversions and I genuinely don't think that it is particularly difficult to end up with a suitably reliable ignition... you just want to avoid the odd known failure points / products.

A common failure point is... if you were to look at a Ducati stator plate base, the allow bit that bolts into the mag housing, you would see that the holes that have wires going through them (from coils to under stator) you would note that the holes are reasonably big diameter and are radiused on the underside. However, look at the cheap Indian stators and these holes are small and straight cut (drilled), leaving them with extremely sharp edges, where the wires turn 90 degrees and rub against this knife-edge corner! I've worked on x-number of failed Indian stators that have not actually failed, other than cut through the wires at this point and taken the ignition to ground. Sort this, as well as use a decent LT (Ceab), epoxy a few points and use some decent connectors and you'll probably have a fairly reliable ignition. Considering how many failed stators are available off mates for nothing / next to nothing, you should be able to do a second to carry a spare too.

Lambretta ignitions... I don't mind them. That said, I have had a couple of pickups fail over the last decade.

Adam

[Micky67keane]

That could be worth a shout.Im not too bad with a soldering iron,so using your instructions should be able to give it a go.May still purchase a Lukas cdi as a backup...Like has been said,its not much fun waiting for recovery.Didnt get home till 3.30am and broke down at 2.50pm

[coaster]

Another thing, is I personally dont like mounting CDI's to the frame and would always attach using rubber bobbins or similar. If I am carrying a spare stator or CDI I wrap them in bubble wrap if they are going in the toolbox

[Micky67keane]

^^^^
Is this to minimise stress due to vibration?
Cheers

[Fast n Furious]

Thanks for the advice,I'll probably fit the Vape and carry a transformer just incase.
Would the one in the link be ok?
https://ebay.us/m/5yYuKT
Thanks for sharing your knowledge

Even a smaller 10VA transformer would do. Just solder on some bullet recepticles to make it almost plug and play.

[coaster]

^^^^
Is this to minimise stress due to vibration?
Cheers

Yes, no electronic device likes vibration, the cdi gubbins are 'encapsulated' in a solid epoxy but that doesnt really protect the large electrolitic capacitor incororated within it.